Parents: Nationalgeographic.com Home
Kids Home
|
NG Kids Magazine
|
NG Explorer Classroom Magazine
|
Games
|
Activities, Experiments
|
Homework Help
|
Kids News
Department of Mineral Sciences, Smithsonian Institution/Dane Penland
1
2
3
4
5
6
7
8
9
10
The big blue stone is made of the hardest natural stuff on Earth. What is it?
diamond
mica
plastic
© 2009 National Geographic Society. All rights reserved.
